A method and an arrangement for detecting a measurement quantity in a vehicle is disclosed in German patent publication 4,040,636. Here, the detection of a measurement quantity is described which is characterized by at least one extreme value which, for example, is pregiven by an end position. This extreme value changes in the course of time so that it is necessary that the extreme value track the changes in order to maintain the needed accuracy of the detection of the measurement quantity. For this reason, a storage value, which represents the extreme value, is corrected under specific conditions at least when the current measurement quantity exceeds or drops below the extreme value in that it tracks the actual measurement quantity with a delay (downward adaptation). With the actuation of the brake pedal, the stored value is changed in the opposite direction (upward adaptation). This procedure ensures that the detection of the measurement quantity retains the necessary accuracy on the basis of the current measurement quantity and the stored extreme value. This procedure has special significance in the detection of the position of an operator-controlled element actuated by the driver such as an accelerator pedal or brake pedal and/or an actuating element such as a throttle flap. It is ensured that defectively stored extreme values do not lead to a malfunction via the upward adaptation when actuating the brake. However, this is true only for the actuation of a brake pedal. This situation does not occur sufficiently often possibly during vehicle operation.